99 POINTS!!!: if i have a circle with a radius of 6 in and it is cut into 8 equal slices (like a pie) and the coordinates are (8, 5) then what is the central angle, what is the measure of the arc that 2 pieces together would intercept, and the equation that represents and circumference?PLEASE HURRY!!!

part 1) 
coordinates of the center (8,5)
radius=6 in
is cut into 8 equal slices-----> 360°/8-----> 45° each slice
a) equation of a circumference
(x-h)²+(y-k)²=r²--------> (x-8)²+(y-5)²=6²

b) circumference=2*pi*r-----> 2*pi*6---> 37.68 in
if 360° (full circle) has a length of---------> 37.68 in
 90° (2 pieces together)---------> x
x=90*37.68/360-----> x=9.42 in

the measure of the arc that 2 pieces together would intercept is 9.42 in

c)  The central angle of one slice is 45 degrees